Vitamin E, particularly in the forms of mixed tocopherols and tocotrienols, has been investigated for its potential role in supporting or treating diabetic retinopathy due to its antioxidant properties. The rationale is based on the fact that oxidative stress contributes to the pathogenesis of diabetic retinopathy, and vitamin E is a well-known lipid-soluble antioxidant that may help mitigate oxidative damage in retinal tissues.

Several small clinical studies and experimental models have examined vitamin E supplementation for diabetic retinopathy. Some trials have reported modest improvements in retinal blood flow or slowing of early retinal changes in diabetic patients, but these studies often have methodological limitations, such as small sample sizes, short durations, or lack of proper controls. Meta-analyses and systematic reviews generally conclude that there is insufficient high-quality evidence to recommend vitamin E as a standalone treatment or preventive agent for diabetic retinopathy. The American Diabetes Association and major ophthalmology guidelines do not currently recommend vitamin E supplementation specifically for diabetic retinopathy.

In summary, while the antioxidant mechanism of vitamin E provides a scientific basis for investigation, the clinical evidence supporting its efficacy in diabetic retinopathy is weak and inconclusive. More robust, large-scale randomized controlled trials are needed to clarify its role. Thus, the use of vitamin E in this context is based on preliminary scientific rationale rather than strong clinical validation.